Spectroscopic Analysis of Plastic Aging During Mechanical Recycling
The collaborative project “SpectralAIge” is developing a novel spectroscopy-based method for reliably assessing the aging of recycled plastics. Modern HSI technology and AI models are intended to enable precise, industry-ready analysis, thereby sustainably strengthening the circular economy. In addition to the SKZ Plastics Center in Würzburg, the Fraunhofer Institute for Factory Operation and Automation IFF in Magdeburg, Silicann Systems GmbH in Rostock, and HAIP Solutions GmbH in Hanover are also participating in the project.
A plastic bottle is irradiated with laser light of various wavelengths and analyzed. This image was generated by AI. (Source: Bertold Zugelder | Adobe Firefly)
The “SpectralAIge” collaborative project develops innovative measurement methods for determining material aging
In the SpectralAIge collaborative project, four partners are jointly developing an innovative measurement method to determine the aging of plastics in order to support a sustainable circular economy. Cyclical recycling within the material cycle leads to material aging and degradation, which can significantly impair the manufacture of new products from recycled materials.
Currently, however, there is no industry-ready method for reliably assessing the degradation status of plastic waste and recycled materials. A decline in quality occurs over multiple recycling cycles, but so far this cannot be reliably predicted.
Combination of modern spectroscopic methods for aging analysis
This is where “SpectralAIge” comes in: By combining modern spectroscopic methods with advanced data analysis techniques, a method is being developed that enables users to make a well-founded assessment of the aging of recycled materials.
Technology deployment and data analysis
To achieve this goal, hyperspectral imaging (HSI) systems, supplemented with LED light sources for targeted fluorescence excitation, are used to record fluorescence spectra of aged samples of common plastic types (PE, PP, PET). Based on the measurement data, both chemometric models—an established tool in polymer analysis—are created, and various artificial intelligence (AI) approaches are tested and systematically compared with one another.
From Research to Industrial Application
The most effective modeling approach is then translated into a software solution that enables automated determination of process-induced aging. Since HSI technology offers high performance but is also cost-intensive, cost-effective inverse spectrometers are being developed as a complement. These are designed for specific use cases with a limited scope—for example, for assessing PET in the returnable bottle cycle—and help ensure broad industrial accessibility of the measurement method.
Practical Focus and Benefits for the Circular Economy
“The findings from the project make a valuable contribution to guaranteeing high product quality and safety in a circular economy. At the same time, in ‘SpectralAIge’ we also focus on the practical, industrial implementation of the results,” explains Cosima Güttler, scientist at the SKZ Plastics Center.
Further information on chemometrics as a tool for polymer analysis
